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Natural Resources
Conservation Service
Ecological site R023XY324OR
SHALLOW SWALE 10-14 PZ
Accessed: 08/17/2024
General information
Provisional. A provisional ecological site description has undergone quality control and quality assurance review. It contains a working state and transition model and enough information to identify the ecological site.
![Location map](/images/maps/R023XY324OR.png)
Figure 1. Mapped extent
Areas shown in blue indicate the maximum mapped extent of this ecological site. Other ecological sites likely occur within the highlighted areas. It is also possible for this ecological site to occur outside of highlighted areas if detailed soil survey has not been completed or recently updated.
Associated sites
R023XY202OR |
SWALE 10-14 PZ Swale 10-14" PZ (no restrictive layer) |
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Table 1. Dominant plant species
Tree |
Not specified |
---|---|
Shrub |
(1) Artemisia arbuscula |
Herbaceous |
(1) Poa nevadensis |
Physiographic features
This site occurs in old lake beds and playas. Elevation ranges from 4400 to 5300 feet. Slopes range from 0 to 2 percent.
Table 2. Representative physiographic features
Landforms |
(1)
Lakebed
(2) Playa |
---|---|
Elevation | 1,341 – 1,615 m |
Slope | 0 – 2% |
Aspect | Aspect is not a significant factor |
Climatic features
Mean annual precipitation ranges from 10 to 14 inches. The majority of the precipitation occurs as snow during December through February. Ephemeral subsurface moisture flow augments this precipitation. The siol temperature regime is frigid. Mean annual air temperatures range from 43 to 45 degrees F. The average frost-free period ranges from 50 to 80 days. The period of primary plant growth is from April through June.
Table 3. Representative climatic features
Frost-free period (average) | 80 days |
---|---|
Freeze-free period (average) | 0 days |
Precipitation total (average) | 356 mm |
Figure 2. Monthly average minimum and maximum temperature
Influencing water features
Soil features
Soils of this site are generally very deep (greater than 60 inches)to bedrock and are somewhat poorly drained. There is a clay layer at 11 inches or less. Ponding on this site is possible between February through May. Surface thickness rnges from 2 to 11 inches. Surface soils are siltloams while subsurface soils are clays, clay loams and slit loams. Soils on this site were formed in alluvium and lacustrine sediments. The available water holdig capacity is about 11 inches. There is a slight potential for wind and water erosion. The shrink-swell potential is high.
Table 4. Representative soil features
Surface texture |
(1) Silt loam |
---|---|
Family particle size |
(1) Clayey |
Drainage class | Somewhat poorly drained |
Permeability class | Moderate |
Ecological dynamics
Range in Characteristics:
Nevada bluegrass decreases and Sandbergs Bluegrass increases on drier sites.
Response to Disturbance:
As the site deteriorates low sagebrush and Sandberg's bluegrass increases in plant density while Nevada bluegrass decreases. Upon further deterioration Sandberg bluegrass decreases.
State and transition model
![Model diagram](/uploads/med/es/es/1728.jpg)
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Ecosystem states
State 1 submodel, plant communities
State 1
Reference State
Community 1.1
Reference Plant Community
The potential native palnt community is dominated by low sagebrush, Nevada and Sandbergs bluegrasses. Vegetative compositionsi about 70 percent grasses, 10 percent forbs and 20 percent shrubs.
Figure 3. Annual production by plant type (representative values) or group (midpoint values)
Table 5. Annual production by plant type
Plant type | Low (kg/hectare) |
Representative value (kg/hectare) |
High (kg/hectare) |
---|---|---|---|
Grass/Grasslike | 392 | 549 | 706 |
Shrub/Vine | 112 | 157 | 202 |
Forb | 56 | 78 | 101 |
Total | 560 | 784 | 1009 |
Additional community tables
Table 6. Community 1.1 plant community composition
Group | Common name | Symbol | Scientific name | Annual production (kg/hectare) | Foliar cover (%) | |
---|---|---|---|---|---|---|
Grass/Grasslike
|
||||||
1 | Perennial, shallow-rooted, bunchgrass | 392–549 | ||||
Sandberg bluegrass | POSE | Poa secunda | 157–235 | – | ||
2 | Perennial, moderately deep-rooted, bunchgrass | 78–235 | ||||
Thurber's needlegrass | ACTH7 | Achnatherum thurberianum | 39–118 | – | ||
squirreltail | ELEL5 | Elymus elymoides | 39–118 | – | ||
5 | Perennial, other | 39–78 | ||||
Idaho fescue | FEID | Festuca idahoensis | 0–39 | – | ||
prairie Junegrass | KOMA | Koeleria macrantha | 0–39 | – | ||
basin wildrye | LECI4 | Leymus cinereus | 0–39 | – | ||
Cusick's bluegrass | POCU3 | Poa cusickii | 0–39 | – | ||
Forb
|
||||||
8 | Perennial, other | 16–78 | ||||
agoseris | AGOSE | Agoseris | 0–16 | – | ||
onion | ALLIU | Allium | 0–16 | – | ||
pussytoes | ANTEN | Antennaria | 0–16 | – | ||
milkvetch | ASTRA | Astragalus | 0–16 | – | ||
hawksbeard | CREPI | Crepis | 0–16 | – | ||
fleabane | ERIGE2 | Erigeron | 0–16 | – | ||
lupine | LUPIN | Lupinus | 0–16 | – | ||
Shrub/Vine
|
||||||
10 | Evergreen | 78–157 | ||||
little sagebrush | ARAR8 | Artemisia arbuscula | 78–157 | – | ||
11 | Deciduous | 24–55 | ||||
rubber rabbitbrush | ERNA10 | Ericameria nauseosa | 16–39 | – | ||
yellow rabbitbrush | CHVI8 | Chrysothamnus viscidiflorus | 8–16 | – |
Interpretations
Animal community
Livestock Grazing:
This site is suitable for grazing under a planned grazing system. Care should be taken not to graze when the site is wet.
Wildlife:
This site will offer food and cover to a variety of wildlife species. It is an important feeding area for non-game mammals and birds. Raptors will also use this site for feeding.
Hydrological functions
The soils of this site have low infiltration rates and low runoff potential. Soils of the site are in hydrologic group D.
Other information
Suitablity for seeding this site is fair because of depth to claypan.
Supporting information
Contributors
Bob Gillaspy
Justin Gredvig
SCS/BLM ESI Team, Hines, OR
Rangeland health reference sheet
Interpreting Indicators of Rangeland Health is a qualitative assessment protocol used to determine ecosystem condition based on benchmark characteristics described in the Reference Sheet. A suite of 17 (or more) indicators are typically considered in an assessment. The ecological site(s) representative of an assessment location must be known prior to applying the protocol and must be verified based on soils and climate. Current plant community cannot be used to identify the ecological site.
Author(s)/participant(s) | Jeff Repp |
---|---|
Contact for lead author | Oregon NRCS State Rangeland Management Specialist |
Date | 08/17/2012 |
Approved by | Bob Gillaspy |
Approval date | |
Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
None -
Presence of water flow patterns:
None -
Number and height of erosional pedestals or terracettes:
None to very few pedestals -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
10-35% -
Number of gullies and erosion associated with gullies:
None -
Extent of wind scoured, blowouts and/or depositional areas:
None, Slight wind erosion hazard -
Amount of litter movement (describe size and distance expected to travel):
Fine - limited movement -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Moderately resistant to erosion: aggregate stability = 3-5 -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Very deep somewhat poorly drained silt loam soils (2-11 inches thick) with clay layer at 11 inches or less: Moderate OM (2-4%) -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Low to moderate ground cover (35-45%) and gentle slopes (0-2%) moderately limit rainfall impact and overland flow -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
None -
Functional/Structural Groups (list in order of descending dominance by above-ground annual-production or live foliar cover using symbols: >>, >, = to indicate much greater than, greater than, and equal to):
Dominant:
Sandberg bluegrass + (Nevada bluegrass) > Low sagebrush > Bottlebrush squirreltail > Thurber needlegrass > other grasses > forbs > other shrubsSub-dominant:
Other:
Additional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Normal decadence and mortality expected -
Average percent litter cover (%) and depth ( in):
-
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
Favorable: 700, Normal: 500, Unfavorable: 300 lbs/acre/year at high RSI (HCPC) -
Potential invasive (including noxious) species (native and non-native). List species which BOTH characterize degraded states and have the potential to become a dominant or co-dominant species on the ecological site if their future establishment and growth is not actively controlled by management interventions. Species that become dominant for only one to several years (e.g., short-term response to drought or wildfire) are not invasive plants. Note that unlike other indicators, we are describing what is NOT expected in the reference state for the ecological site:
Perennial brush species will increase with deterioration of plant community. Cheatgrass winvades sites that have lost deep rooted perennial grass functional groups. -
Perennial plant reproductive capability:
All species should be capable of reproducing annually
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